Machine for hardening gears



3 Sheets-Sheet l G. H. BRYAN MACHINE FOR HARDENING GEARS Filed Feb. 19, 1944 v Juvgnto: $201261: 1H. BRYAN ttorneg June 1 0, 1947.

Q? mm 8 June 10, 1947. G. H. BRYA N MACHINE FOR HARDENING GEARS Filed Feb. 19, 1944 3 SheetsSheec 2 lnfientdr GEORGE IH. BRYAN June 10, 1947. BRYAN' v 2,421,989

MACHINE FOR HARDENING GEARS Filed Feb. 19, 1944 5 Sheets-Sheet 5 GEORGE. 1H.

BRYAN Cittorneg Patented June 10, 1947 mailman HARmi-NING, GEARS ,GeorgeH. Bryan, Brighton, N. Y., .ass ignor tov Gleason Works, RochestenN. Y.',\a corporation of New York Application February 19, 1944, Serial No. 523,081

The present invention relates to machines for surface-hardening gear teeth and particularly to machines for the localized hardening of the teeth of spiral bevel andjhypoid gears in which heating elements, such as oxyacetylene torches, are moved longitudinally of the teeth to bring the teeth up to the required hardening temperature for hardening by subsequent quenching or aircooling. In a morespecific aspect, the invention constitutes animprovement on the surface-hardening machine of the Slade patent, No. 2,102,040, issued December 14, 1937. The machine of the Slade patent and the most generally used types'of machines for surfacehardening bevel gears by the flame-hardening process carry two torches, and these torches are moved simultaneously along opposite sides of a gear tooth to treat both sides of the tooth simultaneously. In the machine illustrated in the Slade patent, the two torches are mountedin a pair of blocks that have transverse sliding movement in a reciprocable ram or slide. The ram or slide is reciprocated to move the torches along opposite sides of a gear tooth from end to end, while the blocks are movable transversely toward and from one another, during movement of the ram, so that each torch may be maintained at a constant distance from the side of the tooth, on

which it is operating, as it moves from one end of the tooth to the other. The transverse movements of the blocks are controlled by two cam rails that are adjustably mounted on the base oi the machine and that are shaped and positioned to maintain the uniform distance between the torches and tooth sides during the movements of the ram.

A primary object of this invention is to provide a surface-hardening machine having a more rigid support for the torches than machines heretofore built. I

A further object of the invention is to provide a surface-hardening machine on which the torches areso mounted that they may move easily and smoothly toward and from one another as they travel from one end of a tooth to the other, so that sticking or binding of the torch carriers will be eliminated.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims.

7 In the drawings: 7

Fig. 1 is a plan view of the torch end of a surface-hardening machine built according to a preferredembodiment of this invention;

2 Fig. 2.is a. side elevationalview of thisjiDart of the machine; f Fig. 3 is a fragmentary plan view on an en larged scale, showing a detail of the torch mountingland' I I Fig. 4 is a part end elevation and a part transverse sectional view of the torch mechanism. i

In the modification illustrated in the accompanying drawings, the invention constitutes an improvement on the torch end of the machine of the Slade patent, and, since the rest of the machine may be of the same structure as shown in .the Slade patent, it has not been deemed necessary to illustrate the rest of the machine."

In the drawings, [0 (Fig. 4) denotes a support or base which may be of the samestructure as the cylinder 82 of the Slade patent. Rivotally mounted on this base or support I 0, as by means of the trunnion 1|, is'a supportingb'racket l2 which serves to carry the torches and their .op'en ating parts. The supporting bracket 12, like the supporting bracket .16 of the Slade machine, may beadjusted angularly about'jthe axis of the trunnion II, to position the torches in the correct angular relation to the work in accordance with the root angle of the work. Mountedin the bracket 12 is a cylinder I4 (Fig. 2) in which the p'istorrl 5 is reciprocal. The piston is secured to a piston rod l6 that projects through one end wall of the cylinder and that isfforrned exteriorly of the cylinder with a ack IT; This rack meshes with a pinion [8 (Figs. 2 and 4) which is inte grill with a spur gear 20. The pinion l8 and spur gear ;are journaled on the trunnion H bymeans of bushings 2|. The gear 20 meshes with a rack 22 which is secured to'a ram'23 by screws 24. The ram 23 reciprocates inaguide way 25 (Fig) 3) formed in the upper face of the bracket l2, and theram is'held in this guide way by the gibs 26 '(Figs. 1, 3,-and 4). i

Mounted on the ram 23 to pivot about the axis o: astud 30 are two arms 3| and 32. These arms are formed on their forward free ends with portions 33 and 34' (Fig. 3), respectively, that ride on the plane upper face of an enlarged j iorward end portion 35 of ram 23. The arms 3| and 32 terminateat their free forwardends in arcuateend surfaces 31 and 38,respectively, which areconcentric with the stud 301A gib 39, which is secured by screws to the head 35 of the ram engagesover the terminal portions of the arms *to prevent canting of "the az'ms3l and 32 in "their rocking movements and to hold them downon the-seat 35. l

- Mounted on the arms ar-an'd'sz and laterally adjustable thereon are the blocks or anvils 4| and 42 (Figs. 1, 2, and 4) respectively. These may be adjusted laterally on the arms by screws 43 and 44, respectively, which are mounted in the arms 3| and 32', respectively, and which thread into the blocks 4| and 42, respectively. The blocks 4| and 42 are secured to the arms in any adjusted position by tightening up the handles 45 and 46., respectively, which engage with bolts that pass through slots in the blocks and that thread into the arms. Adjustment of the blocks 4| and 42 serves to control the distance between the torches in accordance with the pitch of the gear to be treated.

Mounted on the blocks 4| and 4.2. and longitudinally adjustable thereon are bars or rails 49 and 50, respectively. These bars or rails are secured to the blocks by T-bolts (Fig. 4) which engage in slots formed in the bottoms of the bars and which are moved to and from clamping position by the. operating handles 53 and 54, respectively. Pivotally mounted on the forward ends of the bars 49 and 50 by means of hinge pins 55 and 56, respectively. are rocker arms 51 and 58, respectively. Pipes Hand 60, respectively, are secured to these arms. To these pipes are fastened the torch tips 6| and 62, respectively.

The rocker arms 51 and 58 carry adjustable stop-screws 68 which are adapted to engage lugs 18 and [8. respectively, that are formed on the bars 4&- and 50, respectively. Through adjustment of thescrewslitv and 68', the torches can be positioned more precisely, in accordance with the root angle of the work,.and the angular adjustment of the supporting bracket [.2 on the trunnion H is only a. more, or less rough adjustment. When the rocker arms 51 and 58 are swung upwardly about their pivots, the torches are moved clear of theWOrk to permit ready access to. the work.

The torches 6| and 62 may be of any usual, or suitable construction. The oxy-acetylene gas is supplied to the. pipes 59. and 60, respectively, through flexible tubing 63 and 64 which connects with a manifold 65 (Fig- 1) that in turn isconnected through tubing-6'6. with a mixing chamber 51 to'wheih oxygen and acetylenegases are conducted through tubing 69 (Fig. 2). The mixing chamber 51 is supported by a block Hi from the ram 23. The height of the torches can be adjusted by manipulating the'knurled nuts II and 12, respectively, which thread onto the pipes 59 andziill; respectively, and which seat against the upper faces. of the arms 51 and 5.8, respectively. After the torcheshave-been adjusted for height, they may be secured in adjusted positions by clamping bolts which aremanipulatedby handles Hand.

- The arms 3| and 32 are constantly urged away from. one another by the. coil springs 15 and '16 (Fig. 3), respectively, which-are housed in holes drilled in the arms'and which seat. against a pin H that is secured in the ram 23. The arms carry rollers 19. and 80, respectively, which ride on. cam rails ill and 82, respectively, as the ram 23 reciprocates.

The active surfaces83 and 84, respectively, of the cam rails are shaped in accordance with. the lengthwisetooth shape of the gear to be hardened. In the embodiment illustrated, the active surface 83 of the cam rail 8| is of-concave lengthwiseshape and the active surface 84 of the cam rail 82 is of convex'lengthwise shape so that the torches. may follow thelengthwise shapes of opposite sides of a tooth T (Fig.1) of alongitudinally curved toothed gear of zero spiral angle,

that is to be hardened, as the torches move from one end of the tooth to the other in the reciprocation of the ram 23.

'The cam rails 8| and 82 are clamped to the upper face of the bracket l2 by clamping plates 85 and 86, respectively. These plates are secured in position by bolts that pass through elongated slots 81 and 83, respectively, formed in the cam rails and that thread into the bracket I2. These bolts may be manipulated by the hand levers 89. For hardening bevel gears, the cam rails are adjusted angularly with reference to one another so that the torches will converge as they move from the large to the small end of a tooth of the gear being hardened. For the purposes of this adjustment, the cam rails are graduated at one end, as clearly shown in Figs. 1 and 3, to read against zero marks enscribed on blocks 90 and BI, respectively. These blocks are integral with the bracket I2 and extend from the upper face thereof. In

Fig. 1, the cam rails are shown inclined to one another inthe positions which they might occupy when the torches are to move from the large to the small end of a gear tooth on the forward stroke of the ram, while in Fig. 3 the cam rails are shown inclined to one another in the positions which they might occupy when the torches are to move on the forward stroke of the ram from the small to the large end of a pinion tooth.

The means for actuating the ram 23 and for controlling the speed and direction of its movements may be similar to those disclosed in the Slade patent and form no part of the present invention.

Thus, the direction of movement of the ram 2 3, namely, the direction of movement of the piston 5, may be'controlled by a reverse valve mounted in the valve casing 94 (Fig. 1). This valve may be operated in exactlythe same manner as' the reverse valve IOI of the Slade patent above mentioned. It may be moved in one. direction by a'hand lever 95 and in the opposite direction through operation of a trip lug 96 and lock dogs 91. The trip lug 96 is mounted. on the upper face of the ram 23 and is adjustable longitudinally thereof. It maybe secured in any adjusted position by means of a bolt 98 which engages in an elongated slot SP8 that is provided in the face of theram. A scale 93. is secured to. the upper face of the ram adjacent. to the slot'98' to permit. of positioning the trip: lug precisely.

The speed of movement. of the ram may be controlled, as in the Slade patent, by a pair of throttle valves, such as the throttle valves Hi3 and m4 of the Slade patent. These valves may be mounted in a valve casing Hi0 that is secured to the upper face of the bracket 12. One of the valves may be operated by a bell-crank lever |02 which is pivoted at Hi3 on the upper face of the bracket f2 and which is connected through the rod I04 with the valve. The bell-crank lever :ar-ries a roller E95 which rides against a cam .ail IE6. The cam rail W6 is adjustably secured to arail or bar Hi8 by a. bolt, that passes.- through an elongated slot la? in the rail I05 and that threads into the bar I08. Graduations on the rail or bar H18 permit of precisely adjusting the rail )6. The rail MS may be clamped in any adjusted position by manipulating the handle his which is secured to the locking bolt.

The rail, orbar [08 can be. adjusted. angularly on the ram 23 about a pivot pin H2. It may be secured in any adjusted position by abolt that threads into the ram and that is. manipulated by a handleil3. Itmay be positionedprecisely by the graduations on its upper face at its rear end, which read against a zero mark provided on a boss H that is integral with the ram 23. As the ram reciprocates, the roller I will ride on the rails I06 and I08 and the bell-crank lever I02 will be rocked about its pivot I03 causing the throttle valve, which is connected thereto, to vary the speed of movement of the piston l5. Knurled knobs I14 and '5 are provided for adjusting the two throttle valves that control the speed of movement of the ram.

From the preceding description, it will be seen that as the ram 23 is reciprocated on the bracket I2 by operation of the piston l5, rack 16, gears 13 and 20, and rack 22, the arms 3| and 32 will be moved toward or from one another, depending upon the direction of movement of the ram and the shapes and positions of the cam rails 8i and 82. Thus, the torches may be caused to move toward or away from one another as they move along the length of the tooth to be hardened. The construction of the arms 3| and 32 provides a very rigid support for the torches and the rocking movement of the arms assures easy control of their motions from the cam rails without sticking or binding. The cam rails 81 and 82 can, of course, be made of various shapes to suit the lengthwise tooth shapes of the gears to be hardened.

While the invention has been described in connection with a machine such as disclosed in the Slade patent, it will be understood that the features of the invention have other applications, also. Thus, the invention may be employed on a machine in which the work is not stationary during hardening but is rolled under the torches so that they may follow the spiral curvature of a tooth, as is the case in the machine of the Bullock et al. Patent No. 2,294,891, issued September 8, 1942. In general it may be said that while the invention has been described in connection with a particular embodiment thereof, it is capable of still further modification and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth and as fall within the scope of the invention or the limits of the appended claims.

Having thus described my invention, what I claim is:

1. In apparatus for hardening gears, a base, a ram reciprocable on the base, a pair of arms which are pivotally mounted at one of their ends on said ram for oscillation which extends transversely of the direction of movement of the ram, a heating element carried by each arm at its free end, a pair of cam rails fixed to said base and extending in the general direction of movement of the ram, a follower carried by each of said arms intermediate its ends and engaging one of the cam rails, means for holding the followers against the cam rails whereby on movement of the ram, the arms and the heating elements carried thereby are oscillated, a supporting member 7 having an arcuate guide surface secured to each arm intermediate its ends in position to ride on the ram as the arm swings, and an arcuate guide way on the ram with which the supporting members are engaged, the arcuate surfaces of the supporting members and guide way being curved about the pivot point of the arms as a center.

2. In apparatus for hardening gears, a base, a ram reoiprocable on the base, a pair of arms which is pivotally mounted at one of their ends on said ram for oscillation about a common axis that extends in a direction transverse to the direction of movement of the ram, a heating element carried by each of said arms at the free end of said arm, a pair of cam rails fixedly secured to the base and extending in the general direction of movement of the ram, a follower carried by each of said arms intermediate its ends and engaging one of the cam rails, a spring interposed between the ram and each arm at a point between the follower and the arms pivot and operative to hold each follower against the corresponding cam rail whereby on movement of the ram, the arms and heating elements carried thereby are oscillated, a supporting member having an arcuate guide surface secured to each arm at a point between the spring and the free end of the arm and mounted to ride on the ram as the arm swings, an arcuate guide way on the ram with which the supporting members engage, the arcuate surfaces of the supporting members and guide way being curved about the pivot point of the arms as a center.

GEORGE H. BRYAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,102,040 Slade Dec. 14, 1937 2,294,891 Bullock et a1 Sept. 8, 1942 2,322,305 McGuire, Jr June 22, 1943 2,156,884 Sykes May 2, 1939 2,189,460 Derhammer Feb. 6, 1940 2,074,605 Eggemann Mar. 23, 1937 

